Component Analysis

Before reading this page, we strongly suggest a look at this article, which will help you understand the internals of a PSU better.



As I had already mentioned, this is a Seasonic Prime Gold unit based on the Focus platform, but with a separate backplane that hosts the DC-DC converters. Build quality is good, and the parts selection is good as well. On the primary side, Seasonic used a Hitachi bulk cap with more than enough capacity. On the secondary side, the filtering caps are provided by Chemi-Con. Most of them belong to the KY line, which means they will last for a while. Many polymer caps are also used. However, most of those are in the Connect module.


The transient filter has all the necessary components, but still doesn't do a great job given the EMI testing results I got.


There is an NTC thermistor for protection against large inrush currents. A bypass relay supports it for slightly higher efficiency and, more importantly, low temperatures with hot restarts and the bulk cap drained.


Installed on a dedicated heatsink are two GBU1508 bridge rectifiers.


The APFC converter uses two Infineon FETs and a single STMicroelectronics boost diode. The bulk cap is provided by Hitachi, and its capacity is quite large for the PSU's maximum power output, so I expect a long hold-up time. Finally, the resonant controller is the for this efficiency range usual Champion CM6500UNX.


The main switching FETs are installed in a full-bridge topology, and an LLC resonant converter is also utilized to provide higher efficiency levels. The resonant controller is a Champion CM6901T6X.


There is a heatsink on the secondary side, but it doesn't host any FETs. The latter are installed on the solder side of the PCB. Four FETs in total handle the generation of the +12 V rail.


All electrolytic caps are by Chemi-Con and rated at 105 °C. They belong to the KY, KZE, and W lines. The latter is a custom line where the specifications are set by the brand that places the order, so I don't have any detailed information on the W caps.


The supervisor IC is a Weltrend WT7527V, which supports all the necessary protection features but OTP. The latter is implemented through another circuit that reports to the supervisor IC.


Soldering quality is good, although not among the best I have seen.


The fan is by Hong Hua, and its model number is HA13525H12F-Z. This is a quite strong fan for the platform's low thermal loads.


I also broke apart the Connect module for an internal look.


The Connect hosts all modular sockets.


Both VRMs are installed on the Connect module. The common PWM controller is an ANPEC APW7159C.


To keep temperatures low, a heatsink has been placed on the other side of the PCB, where the VRMs are located. A thermistor on the heatsink indicates that there is Over Temperature Protection (OTP), which is indeed the case.


Soldering quality on the Connect module is very good.